Amethyst
Silicon Dioxide (Quartz variety)
gemstone
Category
Mineral, Jewelry
Browse mineral, jewelry specimens identified by the Rock Identifier community.
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Agate Nodule / Chalcedony
Silicon Dioxide (SiO2)
sedimentary
Chevron Amethyst
Silicon Dioxide with Iron Impurities (SiO2)
mineral
Apatite
Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)
mineral
Amethyst
Quartz (SiO2)
mineral
Amethyst
Quartz (SiO2)
gemstone
Blue Aventurine
Quartz (SiO2) with inclusions
mineral
Peridot
Olivine ((Mg,Fe)2SiO4)
gemstone
Chalcedony
Silicon Dioxide (SiO2)
mineral
Fire Opal in Host Rock
Amorphous Hydrous Silica (SiO2·nH2O)
mineral
Sunstone
Oligoclase (Plagioclase Feldspar), (Na,Ca)(Si,Al)4O8
mineral
Amethyst
Silicon dioxide (SiO2) with iron impurities
mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Smoky Quartz (Herkimer-style)
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Mixed Mineral Collection (Quartz, Amethyst, Rose Quartz, Pyrite, etc.)
Mixed Silicates and Sulfides (SiO2, FeS2)
mineral
Goldstone (Brown)
Aventurine glass
mineraloid (man-made)
Turquoise cabochon jewelry
Turquoise, hydrated copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Purple quartz crystal (possibly amethyst)
Quartz, SiO₂; amethyst is purple iron-bearing quartz
mineral
Quartz with Tourmaline
Silicon Dioxide (SiO2) with Schorl (NaFe3Al6(Si6O18)(BO3)3(OH)4)
mineral
Fossilized Shark Tooth
Chondrichthyes (Class)
fossil
Tumbled blue-gray mineral specimen, likely labradorite
Labradorite, a calcium-rich plagioclase feldspar; approximate formula (Ca,Na)(Al,Si)₄O₈
mineral
Amazonite
Microcline Feldspar (KAlSi3O8)
mineral
Pyrite
Iron Pyrite (FeS2)
mineral
Eudialyte
Na15Ca6Fe3Zr3Si(Si25O73)(O,OH,H2O)3(Cl,OH)2
mineral
Amethyst Stalactite Slice
Crystalline Quartz (SiO2) with trace Iron (Fe4+)
mineral
Tumbled yellow-green stone, possibly serpentine
Serpentine-group minerals, commonly antigorite or lizardite; identification from the image is uncertain
metamorphic
Titanium Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Petrified wood
Silicified fossil wood; commonly quartz (SiO₂) replacing woody tissue
fossil
Tumbled Quartz
Silicon Dioxide (SiO2)
mineral
Blue Quartz
Silicon Dioxide (SiO2)
mineral
Diamond (in a jewelry setting)
Carbon (C)
mineral
Wishing Stone
Quartz-veined sedimentary rock
sedimentary
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
Turquoise (set in silver jewelry)
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
mineral
Fairy Stone
Staurolite (Fe2Al9O6(SiO4)4(O,OH)2)
mineral
Agate with Carnelian
Silicon Dioxide (SiO2)
gemstone
Brown Tourmaline
Dravite, NaMg3Al6(Si6O18)(BO3)3(OH)4
mineral
Citrine
Silicon Dioxide (SiO2)
mineral
Tiger's Eye
Silicon Dioxide with Crocidolite inclusions (SiO2)
gemstone